Pediatric Neurosurgery
Core concepts
Know the age-dependent causes of hydrocephalus and the differences between communicating and noncommunicating types. Understand myelomeningocele management (prenatal vs postnatal repair, Chiari II association, tethered cord) and the importance of folate supplementation for prevention. Know the presentation of pediatric brain tumors by location and age: medulloblastoma (posterior fossa, midline, cerebellar), pilocytic astrocytoma (cerebellar, cystic with mural nodule), ependymoma, craniopharyngioma, and brainstem glioma. Understand shunt complications (infection, malfunction) and alternatives (ETV, CPC). Recognize craniosynostosis patterns and when surgery is indicated. Know the basics of Chiari malformation and syringomyelia.
Traps
A frequent trap is confusing medulloblastoma and pilocytic astrocytoma on imaging - the cystic lesion with an enhancing mural nodule favors pilocytic astrocytoma. Another is missing shunt malfunction because the child presents with nonspecific symptoms (headache, lethargy, vomiting). Questions may test that ETV is less reliable in infants under 2 years. Watch for attributing a posterior fossa mass to a tumor when it could be an abscess or hemorrhage.
Worked rule of thumb
In a child with a posterior fossa mass, a midline cerebellar mass with restricted diffusion favors medulloblastoma, while a cystic cerebellar lesion with an enhancing mural nodule favors pilocytic astrocytoma. For shunt malfunction, the first step is imaging and clinical assessment, not assuming infection.